I get these are one way valves but how much leaking is normal? I installed a vacuum pump but with the car off the pump kicks back on after a few minutes and if I cover the exhaust port of the pump it stops the leaking. What is an acceptable amount or should it not leak back at all? I have a spare check valve in the garage and it also would slowly leak air back into the booster. Thanks Cliff
I had an old booster sit for about 4 years and needed the check valve, pulled it and it had strong vaccum.
And there are other booster leak sources on the vacuum side, such as check valve grommet, the big booster o-ring and the booster diaphragm itself...worth keeping all in mind. Devon
First, I think I'd only wire the vacuum pump to the ignition side. Second, anything past the check valve should hold vacuum for quite a while. At least overnight. Do you hear it sucking after the pump cuts off?
I can just barely hear it. I tried blowing air through my spare and I can push air through it the wrong way. Not a lot mind you. For a small few dollar part I don’t know how well they are made as the vacuum from the intake is always pulling but not so with a vacuum pump. And this is just a test before I wire it to a keyed source.. Cliff
